The procedures employed in prior art for producing chip-mounting boards involve the placement of coils for instance on a film carrier into which the individual windings are etched, as described in EP-A2-0 481 776, or of separate, prewound coils which are then mounted on a board substrate either together with the chip as one assembly or as individual components to be connected with the chip on the substrate.
The aforementioned etching process used to apply coil windings on a substrate is very complex and the process lends itself only to coils having a relatively low copper density, which means that transponder units so equipped offer correspondingly low transmitting power. Using prewound coils in the production of a transponder in turn involves complicated coil handling in the insertion and attachment of the coils followed by fusing or gluing the coil to the substrate. Hence, apart from the coiling process proper, additional processing and handling steps are required in producing a transponder unit employing a prewound coil. The overall procedure is thus again quite complex, time-consuming and expensive.